#include <stdio.h>
int main() {
    double n;
    double s = 1, t, q;
    printf("q=");
    scanf("%lf", &q);
    n = 1.0;
    s=0.0; 
    while (s < q) {
        t = s;
        s = s + (n + 1.0) / n;
        n++;
    }
    printf("n=%lf:%lf\n", n, s);
    return 0;
}
